diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f02620cb..307fa755 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -27,6 +27,10 @@ jobs:
         with:
           submodules: recursive
 
+      # needed for depext to work
+      - run: sudo apt-get update
+        if: ${{ matrix.os == 'ubuntu-latest' }}
+
       - name: Use OCaml ${{ matrix.ocaml-compiler }}
         uses: ocaml/setup-ocaml@v2
         with:
diff --git a/dune-project b/dune-project
index 93d60bb3..e876d9d0 100644
--- a/dune-project
+++ b/dune-project
@@ -28,6 +28,7 @@
  (depends
    (ocaml (>= "4.08"))
    (opentelemetry (= :version))
+   (cohttp-lwt-unix :with-test)
    (odoc :with-doc)
    lwt)
  (tags
diff --git a/opentelemetry-lwt.opam b/opentelemetry-lwt.opam
index 207d329b..526ba1de 100644
--- a/opentelemetry-lwt.opam
+++ b/opentelemetry-lwt.opam
@@ -13,6 +13,7 @@ depends: [
   "dune" {>= "2.7"}
   "ocaml" {>= "4.08"}
   "opentelemetry" {= version}
+  "cohttp-lwt-unix" {with-test}
   "odoc" {with-doc}
   "lwt"
 ]